High speed molded wheel and process therefor



March 5, 1963 w. J. cosmos 3,079,645

HIGH SPEED MOLDED WHEEL AND PROCESS THEREFOR Filed Nov. 25, 1957 2Sheets-Sheet 1 a 1 i V 3 21 P J 5. 4.5 J 36 I J Y J, jg INVENTOR. 19 5 11/ J6 /zZ/z'afiz J [as/mas.

w. J. cosmos 3,079,645

HIGH SPEED MOLDED WHEEL AND PROCESS THEREFOR 2 Sheets-Sheet 2 M BY March5, 1963 Filed Nov. 25-, 1957 llnited States fP atent 3,979,645 HIGHSPEED MGLIEED WHEEL AND PROCES THFJREFGR William 3. Cosmos, 651 MarketSt, Waulregan, ill. Filed Nov. 25, 1957, Ser. No. 698,669 4 (Zlahns.(62. 18-49) The invention relates to improvements in industrial wheelunits and more particularly to high speed contact wheels for grindingand polishing machines employing revolvable coated abrasive belts orsleeves; roller sections for industrial rollers; expanding wheels formounting abrasive belts and sleeves; and to the method of manufacture ofsuch wheels and wheel units. In the use of a high speed contact wheel anabrasive belt is trained over and revolved at a high speed around-one ormore such wheels and it is eilectively supported thereby for thepresentation of the work thereto. Such Wheels, as well as wheel units,roller sections and expanding wheels, have a resiliently yieldable rimor working periphery, which, in some applications, is treaded toaccommodate variations in a belt trained thereover and/or in the workpresented thereto, to facilitate cooling and to prevent prematurewearing of the belt, and marring, marking or mutilation of the work, tomake the wheel more or less aggressive, and to provide firm binding ofthe belt or sleeve over the wheel while it is in rotation.

Wheels, roller sections, wheel units and expanding wheels of thisgeneral character are operated at high speeds, usually in excess of 1500revolutions per minute, and they comprise, generally, a mounting hub andconcentric flanges forming a peripheral surface connected. to the hub bya web. More specifically, one example of such a prior type of wheelstructure has the hub, web and peripheral surface formed as a unit, asby casting; the flanges thereof extending in opposed directions on eachside of the web. The resiliently yieldable rim or working periphery iswrapped around and bonded to the outside circumferential face or" saidperipheral surface. The rim, it smooth surfaced, is then milled orotherwise formed in any conventional manner with circumferential and/orlaterally directed channels, grooves or slots, so as to provide aperipheral working surface having a multiplicity of ribs, lands orislands, each having the requisite resiliency and yieldability tofunction for its intended purpose. The working surface is then dressedso as to insure uniformity of diameter and dynamic balance.

The construction of such a known type of industrial wheel structureinvolves an excessive amount of costly labor and time, and it istherefore, an object of the invention to provide a novelly constructedinexpensive industrial wheel structure of the characte herein referredto.

Ordinary industrial wheels or wheel units of known types tend to wobbleto some degree, particularly when used singly, while operating with ahigh power output, primarily because of the inherent resiliency of thestock comprising the web. Such wobble causes lateral shifting of a belttrained thercover, and furthermore, there is sound generation, unevenwear on the belt, sleeve, arbor, or wheel unit itself, and the danger ofwheel explosion is great. It is therefore another object of theinvention to provide a wheel structure with novel means to prevent suchwobble.

During high speed operation of a wheel, the bonded resiliently yieldableperipheral rim is subjected to tremendous centrifugal forces which tendto expand the rim outwardly radially and should the bonding of the rimto the metal web flange be inadequate, or should there be air pockets inthe rim material, the rim is liable to become ruptured and disintegrate,in which event serious injury may result to the operator and the machinedamice aged. The present method of construction and the resultingstructure of the wheel itself is such that the rim is adequately bonded,not only to the peripheral web flanges, but also is integral with a bodyof the same material that is held between and bonded to the opposedfaces of the web discs and consequently is so reinforced as to withstandthe damaging influence of the centrifugal forces generated during use.it is therefore another object to provide a wheel structure of thecharacter described with novel means to prevent disintegration by reasonof centrifugal forces.

Another object is to provide a novel method and means for forming anintegral wheel structure embodying the novel features herein described.

Hcretofore, considerable difliculty and expense has been involved inmaking wheel structures having peripheral working rims of diderentwidths and with a web proportioned in thickness to the rim width so asto insure adequate rigidity to the finished wheel. Such variation occursin instances of integral wheels, segmental wheel units, roller units, orexpanding wheels having different face widths and web thicknesses. Thesecan be made in the same mold or dies with but slight modification orsubstitution therein. The modification or substitution is easily andquickly accomplished by practice of the herein disclosed novel method ofconstruction, and it is therefore another object of the invention toprovide a novel method of manufacture which is readily adaptable formaking contact wheels or wheel elements of diderent widths and havingdlfierent degrees of rigidity in the web portion thereof.

Another object is to provide a novel sectionalized industrial roller.

With the foregoing and other objects in view which will appear as thedescription proceeds, the invention consists of certain novel featuresof construction, arrangement and combination of parts hereinafter fullydescribed, illustrated in the accompanying drawings, and particularlypointed out in the appended claims, it being understood that variouschanges in the form, proportion, size and minor details of the structuremay be made without departing from the spirit of sacrificing any of theadvantages of the invention.

Referring to the drawings in which the same characters of reference areemployed to indicate corresponding or similar parts throughout theseveral figures of the drawing:

FIGURE 1 is a diametrical section view of the novelly assembled contactwheel.

FIGURE- 2 is a diametrical sectional view of the die or mold assembly,showing the dies in open position and the wheel material positionedtherein.

FEGURE 3 is a view similar to FIGURE 2, showing the die assembly closed.

FlGURE 4 is a peripheral view of a segmental contact wheel, showingparts in section.

FIGURE 5 is a peripheral view, partly in diametrical section, showing anexpanding wheel embodying the features of the invention.

FEGURE 6 is a peripheral view of an industrial roller built up ofremovable and interchangeable sections each constructed by the hereindisclosed method.

FEGURE 7 is a fragmentary diametrical sectional view of a wheel unit,embodying a modified form of con struction.

The high speed contact wheel and wheel units disclosed herein andembodying structure for overcoming the aforementioned disadvantages andcharacteristics of known types of wheel structures, is made by pressuremolding in a heated die assembly. It comprises essentially, a pair ofperipherally flanged web discs tabricated, as by stamping, from sheetmetal stock, which are seated in the open die, and which have a mass ofunvulcanized rubber, natural or synthetic, of predetermined volumeplaced therebetween. The dies of the die assembly include a tread or rimforming cavity and when the dies are moved toward one another (usuallyat a pressure of approximately 2090 lbs. per square inch) as is commonpractice during the molding operation, the unvulcanized rubber mass isdistributed evenly between the web discs at a thickness determined bythe setting of'the discs, and the rubber extruded from between the discsflows outwardly radially into and fills the rim forming cavity which mayor may not include landor tread forming configurations; The whole isthen heat treated or cooked at temperatures ranging-from about 280 F. to320 F. for a period of time required to vulcanize the rubber and tobondit firmly to the contacted metal surfaces of theweb discs. When thewheel structure is removed from the die it is mounted on-an arbor:androtated :at high speeds, and dressed. The

amount of .dressing required is nominal and is primarily for the purpose.of-obtaining a dynamic balance in the wheel, and for removing thecentral circumferential area of thejperipheral worksurface which bulgesoutwardly at the circumferential center owing to applied centrifugalforces. The dressed wheel unit structure, when idle, will therefore havea slightly concave surface laterally, which surface assumes a flatcondition during rotation of the Wheel.

The contact wheel illustrated in FIGURE 1 is fabricated in anovel mannerto be described presently. It comprises a pair of circular web plates11, fabricated, as bystamping, from heavy guage sheet metal stock,having-aligned axial openings 12 and each is formed on its outerperimeter with a peripheral flange 13. When assembledin a contact wheel,the web plates 11 are maintained in spaced relation one to the other bythe presence of a layer of rubber14 of predetermined thicknesstherebemeen and with their peripheral flanges extending outwardly inopposite directions. These flanges constitute a peripheral surface uponwhich is bonded a resiliently yieldable rim or working periphery 15 thatis integral with the intermediate layer of rubber 14. There is thusprovided a contact wheel 10 having a resiliently yieldable workingperiphery or rim that is bonded firmly to the plate flanges '13 and isintegrally connected to a'layer-of rubber. 14 interposed between andbonded to the opposed facesof the plates 11.

The web plates 11 and the layer 14 therebetween constitute the web ofvthe contact wheel and because of the increased thickness afforded saidweb by the presence of the interposed layer 14 and the fact that thesaid layer is 'bonded firmly to both discs, said web flat resistsdistortion while the wheel is in use and accordingly avoids wobblesooften present in wheels constructed according to prior knownpractices. The presence of the web layer 14 has other distinctadvantages which will become apparent as the description proceeds. I

The contact wheel 10, as well as the wheel units and segments disclosedin FIGURES 4, 5, 6 and 7, and later described, disclosed in FIGURE 1, isfabricated in a novel manner'by a simple inexpensive one-step moldingmethod illustrated in FIGURES 2 and 3. The entire wheel is made in oneintegrated body of metal and rubher by-a moldingprocess in a heated dieassembly generally indicated at 16. As shown, the die assembly includesa lower die 17 which-is'comprised of a central die portionIS'and'asurrounding die portion or collar19, and an upper die 21. Oneofthese dies 17 or 21 is stationary, while the other one is carried on avertically recip-.

rocal hydraulically plunger (not shown) for movement vertically towardand awayfrom the first named die.

The said upper-die 21 has a downwardly facing diesurface formed with anannular downwardly offset surface 22 Ma diameter'corresponding to thediameter of a web plate 11 and terminating at its perimeter in ashoulder 23 and a surrounding annular surface 24. The shoulder 23 is ofa height correspondingsubstantially to the width of the flange 13 on oneof the web plates 11, so that when said one plate is placed over thesurface 22, as is best shown in FIGURE 2, its flange 13 embraces theshoulder 23. The plate, and its flange, is thereby firmly backed by thedie surfaces 22-23.

The other or lower die 17 of the die assembly is arranged below and inaxial alignment with the upper die 21. The central die portion '18 is ofsuch size as to receive the-reover the other web plate 11 which plate isseated on. the top face of the die and has its peripheral flange 13snugly embracing an annular shoulder 25 surrounding said die surface.The surrounding die portion or collar 19 constitutes the peripheral rimof the die assembly and this collar is recessed on its upper face, as at26, to provide a cavity in which thepworking surface or rim 15 of thecontactwheel is formed in a manner to be described presently.

;As shown, the collar19 has an upper peripheral edge 27 which is carriedinto surface contact with the surrounding surface 24 of the upper diewhen the dies are in the closed position shown in FIGURE 3. The verticalinside annular surface 28 of the recess or cavity 26 may be smooth oritmay be formed with inwardly facing ribs or other mutually spacedprojections 29 adapted to form the lands 31 on the working periphery orrim 15 which is formed in the cavity. In either event, the annularsurface 28 terminates at its lower end in a planular surface 32 which isin horizontal alignment with the downwardly disposed free edge of thebottom web plate flange 13 car: ried on the central die portion 18.

If desired, either one of the dies 17 or 21 may carry an axiaLpost 33adapted to extend through the axial openings 12 in the web plates 11 andtelescope into an axial recess 35 in the other die when the dies areclosed. In the present disclosure, the post 33 is carried by the lowerdie portion 18.

The molding of a wheel structure of the character 'herein disclosedinvolves the placing of a web .plate 11 on the lower die, asillustrated, while said dies are separated. The exposed face of saidplate 11 preferably is roughened by sand blasting and is coated with abonding adhesive. A predetermined mass 34 of unvulcanized rubber,natural or synthetic, is then placed upon the top surface of said webplate whereupon the upper die 21, carrying the other web plate 11,similarly coated, is oved relative to the die 17 andsufficient pressureis maintained on the mass sandw'iched-therebetween to compress the massbetween the matched web plates 11. The pressurizing is accomplished inthe presence of suflicient heat, supplied to the die assembly in anysuitable manner, such as for example through ducts 36 therein, so as tomaintain the rubber mass in pliable state.

Thedistance of travel of the upper die 21 relative to the lower dieassembly 17 is limited by contact between the peripheral edge 27 of thesurrounding die collar 19 with the surface 24. This distance is suchthata predetermined quantity of the rubber mass is uniformly distributedbetween the web plate 11 with the excess rflowing outwardly radiallyinto the cavity 26 so as to fcgm the working periphery or rim 15 of thecontact w ee with a bond resisting powder or like substance. This powderor like substance is not brushed or wiped 'ofi by the radial flow of theextruded rubber into the cavity, as so often occurs when the mass isflowedinto the rim cavity through a feed opening in the peripheral wallof a die assembly. Any material in excess over the amount required tofill th space between the plates and in the cavity, may escape throughbleeder holes 37 provided in an adequate number in the dies 1721, whichholes also insure proper bleeding of any ,air trapped in the, die duringits closing operation.

The walls of the cavity 26 are previously coated The closed dieassembly, with the rubber properly distributed therein, is allowed toremain closed for a time required to effect vulcanization of the rubberand its firm bonding to the opposed faces of the web plates 11 and tothe peripheral flanges 13 thereof, after which the die assembly isopened and the contact wheel 11 is removed.

'In the event that it is desired to provide hub portions 38 on each sideof the web, this may be eflected during the molding operation. To thisend, the upper die 21 and the die portion 13 of the lower die may eachbe formed with an axially concentric cavity 39 of such size as toreceive therein one of the rubber hub portions 33. These hub portionsare in surface contact with the outside faces of the respective webplates 11 and they are firmly bonded thereto during the pressurizedvulcanizing operation previously described.

It should be quite evident at this time that applicant has provided anovel means for pressure molding a wheel structure wherein the rim orworking periphery thereof is bonded firmly to the flanges of the metalweb plates and is integral with the reinforcing layer of materialdistributed evenly between and bonded to said plates. The thickness ofthe interposed layer and the width of the rim may be varied byincreasing or decreasing the ef fective depth of the perimeter wall 28of the die collar 19'. Consequently, the herein disclosed process andmethod may be employed in the production of contact wheels, or wheel orroller units, of different face width and web thickness with but aslight variation in the equipment utilized.

FiGURE 4 shows a wide faced contact wheel composed of three wheel units16a, each corresponding in structure to contact wheel it? in FIGURE 1,which are made by the herein disclosed method. Wheel unit Ida differsfrom wheel it in that web layer 1411 is thinner than web layer 14, andthe Wheel unit has a narrower peripheral face or rim 15a. The thinnerweb layer 14a in a wheel unit is satisfactory because of tightface-to-face abutment of the units which affords rigidity to the wheelassembly.

FIGURE 5 shows an expanding wheel or hub unit ltib fabricated like thewheel and wheel units and lilo. Expanding wheel 10b is designed toreceive slidably thereovcr working sleeve 41 which is firmly held duringrotation of arbor 42 by centrifugal expansion of threaded periphery rimb. This wheel has a thick web layer 14b integral with rim 15b and bondedbetween web plates 1112.

FIGURE 6 shows an industrial roller 43 composed of severalinterchangeable and replaceable roll units 160, each of which is made bythe within discribed method and which includes a thin web layer 24cbonded between web plates 11c and integral with its peripheral rim 15c.These roll units may be smooth surfaced, as shown, or they may betreaded as required.

FIGURE 7 shows a contact wheel unit fabricated in the same manner as thewheels and wheel units described hereinabove. In this instance the w eelunit includes a pair of sheet metal web discs 11d which are devoid ofany peripheral flanges. Instead the peripheral margins of the discs areembedded in and bonded to the resilient peripheral rim 15d, as at 44,and said rim is integral with the resiliently yieldable web layer 14dinterposed between and bonded to the opposed faces of the web discs.

A contact wheel, roller unit or wheel unit, made according to theteachings herein disclosed will have a longer wearing life and will notwobble during high speed working operations. When such wheels arerotated at high speeds required for eflicient use, the centrifugal forceacting on the rimis transmitted throughout the entire body of theintegral layer of rubber between the web plates with the result thatsuch radial stress i substantially absorbed by the said layer thusreducing the CPI 6 likelihood of the rim tearing loose from theperipheral web flanges to which it is also bonded. Furthermore, thetensioning of the web layer between the Web plates to which it isbonded, in response to contrifugal force, not only reduces the inherentflexibility of the web structure, but it also exerts a lateral forceinwardly on each web plate so as to increase the rigidity of said webplates and thereby eliminate all tendency of the web to wobble.

Although rubber, natural or synthetic, is suggested herein as thematerial best suited for the fabrication of the rim and the web layerintegral therewith, other elastic or resilient.y compressible moldablematerial capable of tight bonding to metal may be used, and in a Widerange of densities for different specific uses.

It is believed that the invention, its mode of constrnction andassembly, and many of its advantages should be readily understood fromthe foregoing without further description, and it should also bemanifest that while preferred embodiments of the invention have beenshown and described for illustrative purposes, the structural detailsare nevertheless capable of wide variation within the purview of theinvention as defined in the appended claims.

What is claimed and desired to be secured by United States Letter Patentis the following:

1. The method of making an industrial Wheel in a mold assembly whichcomprises the placing of a disc having a circumferential flange on itsouter periphery and extending from one face thereof onto a mold surfacewith the flange extending downwardly, arranging a mass of unvulcanizedrubber of predetermined volume upon the upper face of said disc, placinga like disc over the mass with its flange extending upwardly, pressingthe discs toward one another to distribute the rubber uniformly betweenthe discs and cause a portion thereof to be extruded outwardly radiallybeyond the flanged peripheries of said discs, molding the extrudedrubber into a circumferential rim on the outside circumferential facesof said flanges, and finally vulcanizing and bonding the rubher to theopposed faces of the discs and to the flanges.

2. The method of making an industrial Wheel of a type having spacedcircular metal plates bonded to an intermediate layer of rubber and arim integral with said layer and embedding the peripheral margins ofsaid plates, said method comprising placing one plate in a circular moldcavity having a rim forming cavity into which the peripheral margin ofsaid plate projects, arranging a mass of unvulcanized rubber ofpredetermined volume on said plate, placing a second like plate oversaid mass with its peripheral margin extending into the rim formingcavity, pressing the plates toward one another to distribute the massuniformly between the plates and cause a portion of said mass to flowoutwardly radially and fill the rim forming cavity and embed theperipheral margins of the plates therein, subjecting the molded wheel toheat to vulcanize the rubber, removing the molded wheel, and finallymounting the wheel on a rotating arbor and dressing the peripheralsurface of its rim.

3. The method of molding an industrial wheel of a type having spacedcircular metal plates bonded to an intermediate layer of rubber and arim integral with said layer and embedding the peripheral margins ofsaid plates, said method comprising placing one plate in a circular moldcavity having a rim forming cavity into which the peripheral margin ofsaid plate projects, arranging a mass of unvulcanized rubber ofpredetermined volume on said plate, placing a second like plate oversaid mass with its peripheral margin extending into the rim formingcavity, and then heating the said mold and pressing the plates towardone another to distribute the mass uniformly between the plates andcause a portion of said mass to flow outwardly radially and fill the rimforming cavity and embed the peripheral margins of the plates therein.

4. The method of molding an industrial Wheel of a type having spacedcircular metal plates bonded to an intermediate layer of rubber and arim integral with said layer and embedding the peripheral margins ofsaid plates, said method involving the use of a circular mold having hubcavities and a rimforming cavity, placing rubber hub members one in eachhub cavity, arranging a pair of like plates one over each hub member.with their peripheral margins projecting into the rim forming cavity,arranging a mass of unvulcanized rubber of predetermined volume betweensaid plates, pressing the plates toward one another to distribute themass uniformly between the plates and cause a portion of said mass toflow outwardly radially and around the projecting plate margins and fillthe'rim forming cavity, subjecting the molded wheel to heat to vulcanizethe 8. rubber and bond it to the plates, and finally dressing theperipheral surface of its rim. References Cited in the filepf-this-patent UNITED STATES PATENTS 1,686,142 Bansieur Oct. 2, 19281,947,695 Carthew Feb. 20, 1934 2,137,937 Smith Nov. 22, 193;; 2,439,90.Pi ron Apr. 20, 19.48 2 ,674,897 Heinish Apr. 13, 1954' 2,760,378 VanDeventer Aug. 28,1956

7 FOREIGN PATENTS 1,101,559 France a Oct. 7, 1955 0 8 Germ n ---V---ly1932 V 675,679 Great Britain July'l6, i952

1. THE METHOD OF MAKING AN INDUSTRIAL WHEEL IN A MOLD ASSEMBLY WHICHCOMPRISES THE PLACING OF A DISC HAVING A CIRCUMFERENTIAL FLANGE ON ITSOUTER PERIPHERY AND EXTENDING FROM ONE FACE THEREOF ONTO A MOLD SURFACEWITH THE FLANGE EXTENDING DOWNWARDLY, ARRANGING A MASS OF UNVULCANIZEDRUBBER OF PREDETERMINED VOLUME UPON THE UPPER FACE OF SAID DISC, PLACINGA LIKE DISC OVER THE MASS WITH ITS FLANGE EXTENDING UPWARDLY, PRESSINGTHE DISCS TOWARD ONE ANOTHER TO DISTRIBUTE THE RUBBER UNIFORMLY